1. Field of the Invention
This invention pertains to railway freight cars and in particular to a door operating handle and associating mechanism that provides a braking device to retard inadvertent movement of the car door unless the handle is moved from a normal upright position.
2. Description of the Prior Art
Several prior art devices have provided means for retarding movement of freight car doors when in an unlocked or open position. For example, the Howard et al. U.S. Pat. No. 1,390,786 (1921) shows an extensive handle, lever, rod and cam arrangement for retarding door movement. Similarly, the Cookingham et al. U.S. Pat. No. 1,042,326 (1912) also shows a lever and wedge-lock type of linkage arrangement for retarding movement of the door when it is an unlocked or open position. Neither of these devices has met with widespread acceptance because of the elaborate hardware that must be attached to the car door and because of modifications in the door structure required to adapt the door for use with these devices.